23.9. Synchronize to PTP or NTP Time Using timemaster

When there are multiple PTP domains available on the network, or fallback to NTP is needed, the timemaster program can be used to synchronize the system clock to all available time sources. The PTP time is provided by phc2sys and ptp4l via shared memory driver (SHM reference clocks to chronyd or ntpd (depending on the NTP daemon that has been configured on the system). The NTP daemon can then compare all time sources, both PTP and NTP, and use the best sources to synchronize the system clock.

On start, timemaster reads a configuration file that specifies the NTP and PTP time sources, checks which network interfaces have their own or share a PTP hardware clock (PHC), generates configuration files for ptp4l and chronyd or ntpd, and starts the ptp4l, phc2sys, and chronyd or ntpd processes as needed. It will remove the generated configuration files on exit. It writes configuration files for chronyd, ntpd, and ptp4l to /var/run/timemaster/.

~]# service timemaster start

~]# service timemaster start